My first jump of the year and it dawned on me that, after exiting at 12k and enjoying the scenery on a chilly belly fly that my alti had worked til 9k (checked it at 11k 10k )....

at 9k it stopped - I realised, nice and calmy, that the ground was coming [but I had plently of Altitude] - but the alti was not - so I gave it a tap and it showed 4500 and I waved off and pulled. My normal pull is 3500 but, as i didn't know my altitude for sure I simply pulled as per aff training - if you dont/cant be sure of your altitude then pull. I am a noob (44 jumps) and was wondering if there was anything alse to add to this that would help when it happens again.

the alti was a new alti 2 that had worked my last 20 jumps. Obviously the alti is now grounded until it goes back to the dealer for repair.

It sounds like you did a good job following your training. If you don't know the alt, pull.

I had to send my alt off for repair because it was lagging about 800 feet behind where it should be. The first trip for repair did not fix the problem. The company made it right in the end. In the mean time I purchased a used spare. I now have a wrist mount and one on my mudflap. Just by my experience and what you have seen with that unit, I would not trust the repair until it had proven itself with many jumps. Carry a second unit if you have the option.

A good way to start calibrating your MK1 altimeter (your eyes) is to play "guess your altitude".

Whenever you have a good view of the ground during the climb to altitude, look outside and guess your altidude. Then check what your alti reads. You will start to dial in your internal altimeter. If you always jump at one DZ, how big does the hanger look at various altitudes. How long is the runway? Also learn relative sizes of objects that are the same everywhere. The size of a car or lorry, the width of a 2 or 4 lane road, etc. This will be helpful when you travel and don't know the size of the local hanger, but these other clues haven't changed.

There comes a point in the skydive where you fall out of the blue umbrella and into the green bowl.... it's down around 4k to 3.5 k YMMV. You can tell by just using your eyes and watching this transition, it's subtle when it happens, most people never see it on a skydive, it's where while up high you are in blue umbrella, the blue sky surrounds you, the horizon is way out and below you and as you get lower and lower at some point you enter into the green bowl where the horizon is now even with you and not below you, the lower into the green bowl you go the high up the horizon is for you to look at it.

Once you down in there things are moving fast and you should be doing things, there for it's easy to miss seeing the clues, they are there though.

I waved off and pulled. My normal pull is 3500 but, as i didn't know my altitude for sure I simply pulled as per aff training -

Not a bad idea on a solo. Another thing to think about, as per AFF training, is to keep your altitude checks frequent and on a regular interval.

Do a manuver, check your altitude. Do another manuver, check again. The idea here is that when you look at see 9k twice in a row, you're not wondering how long it had been since the first time you saw 9k. If you check every 10 seconds, you see 9k twice, then you know that you're 'about' 10 seconds past 9k, or conservatively around 7k.

Another idea when you're doing solos is to combine the alti checks with a visual ground reference check. Alti says 7k, glance down to see what that looks like. It will help you to get an idea of what the ground looks like. That's not an exact science, as different DZs, different times of year, and different levels of visibility will effect what the ground looks like, but it's just more information for you to have and work with, and that's always good.

As you move off of solos, you will have other jumpers to reference as well. If your alti appears to be stuck, I would NOT just wait for the other jumper(s) to break off, but you can make an effort to try and see their altimeter (easier during RW, not as much when freeflying). Again, all this will do is add more info for you to make a decision, but it's something.

Of course, when jumping with others, you need to rethink the idea of 'just pull'. On a jump where you can see EVERYONE, you have more options, but if you can't see everyone, or are not 100% sure, just pulling is a bad idea (sometimes). In any case with others, you do need to turn and track to some degree, more so if you don't know where everyone is.

The catch is that there's a difference in how you lose altitude awareness. If you have a stuck alti, and appear to be mid-jump with others, you do need to consider them when you decide what to do. If you lose awareness to the point that you are all low, and your life is in danger if you don't pull very soon, then some things change. Maybe just turn 180 and dump, and take a chance with regards to the other jumpers, but this is when you're going to die otherwise.

I know you like to pull at 3500, but if you find yourself in freefall with grips at 3500, that's not an emergency. It's a mistake, but you still have time to turn and track (not for long) before you dump. The time to go 'quick draw' on your PC is when you smoke through 2k with grips, and you're going to hit the planet hard in 10 or 12 seconds.

It's tricky business, and the above are all great reasons to properly equip yourself with the right gear (visual and audible alti) and the right information (have a plan ahead of time, train your eyeballs to help you), and then to work really hard every jump not to make those sorts of mistakes and put yourself into those situations.

I have a giant Alti 2. people on the plane always point to it because it gets stuck and won't read right till I tap it. It flows fairly well when changing altitude in freefall but it's still just not a very accurate altimeter overall.

I have a giant Alti 2. people on the plane always point to it because it gets stuck and won't read right till I tap it. It flows fairly well when changing altitude in freefall but it's still just not a very accurate altimeter overall.

It needs repair/maintenance. How long are you going to jump it and complain about it before you get it fixed?

How accurate do you need it to be? Down low in the pattern you aren't using it anyway.

You're right. I wouldn't advise on anyone just relying on judging their own impression of time passing as the sole measure of when to pull. More specifically that you're, say, 10 seconds into the jump and then on alti check expect to see a certain altitude having passed. If it wasn't the case then you know something is wrong with the instrument.

+1. Get ground reference points with an operating altimeter and then calibrate your eyes and brain.

And do that on EVERY jump!

As was said in several posts above, ya need to train your eyes...THEY are your primary altimeter.

In the aircraft look outside and get a mental snapshot of critical altitudes.

Hard deck, pull time, break off...make a conscious effort to 'ingrain the terrain' so to speak.

How big are the cars, the buildings, the roads,

Use the 'blue umbrella' technique by looking out at the horizon 'wide angle' during the climb to altitude and visualizing 3-D, the view on the way back down.

It's like everything else in the sport, it takes some time & practice to get proficient. Practice it on the way up AND the way down...you'll get the hang of it pretty quick.

It's one of the more important 'skills' of survival so give it that kind of attention.

You never know when an altimeter will fail.

Later on you may lose awareness during a dive due to concentration on the RW or whatever, seeing the 'green bowl' in your peripheral vision sets off an alarm in your head ~ if you've conditioned yourself that way.

It's saved a lotta lives over the years.

~ and just to touch on a point: I don't know why so many people have problems with their altimeters.

Certainly anomalies occur and no product is perfect, but watching 'in general' how some people treat that thing... leaves little question in MY mind that some of the problems are abuse induced.

Yes they're designed to operate in a tough environment, but keep in mind it's still a somewhat fragile precision instrument.

Expose a BRICK to enough heat, dirt, moisture, vibration, hard impacts & IT ain't gonna last too long...imagine what all that does to the hard working Leprechauns inside your altimeter!

I have two altimeters~ an Alti II that I bought 30 years ago, only thing I've ever 'fixed' is the wrist straps which wear out...still works perfectly and look almost new.

A Neptune a bought from a buddy 5 yeas ago, also looks & works like new.

I take good care of 'em when I wear them & even better care when I'm not...No hot trunk storage, no pressure bumps from slamming trunk lids, never thrown, dropped, hit with anything (like a helmet in a gear bag) - like a camera, an iPod or a nice watch, treat 'em with care & keep them in a padded case.

The guess my altitude game should just be a part of your routine on the way up and on the way down.

you can have more than one alti

I have 3. An audible in my helmet, a neptune on my hand, and an analog galaxy on my mud flap. A failure of any one of the three should not leave you to your eyes alone.

if you are in a group stick to the plan

One point I'm not sure anyone quite made is that the "if in doubt pull" plan is a really really bad one if you're in a group.

plan the dive and dive the plan.

If the plan is to break at 4.5 and pull by 3.5 and sometime between exit and before breakoff you see your only alti isn't working, stick with the plan and your dive. when they break, you break, do a short track, and pull.

Note: don't get complacent and just assume they're going to do the right thing. Still use your eyes. But if you have 2-3 other people stick close to them and break when they do as long as your eyes aren't telling you that you're too close to the ground.

look at clouds

make mental notes of cloud altitudes on climb up.

feel the temperature

if it's summer the ground is going to be warmer and more humid than high altitude. if you are in free fall hauling ass and you feel it get suddenly warmer and wetter that might be a clue that you're burning through 2k or worse.

in short: there are tons of sources of information you can use in addition to your altimeter. Use them. Even when your altimeter is working, look for them and use them.

I have a giant Alti 2. people on the plane always point to it because it gets stuck and won't read right till I tap it. It flows fairly well when changing altitude in freefall but it's still just not a very accurate altimeter overall.

The Alti-2 company is VERY good about doing repairs and replacing faulty altimeters. kat and Roger used to travel the boogie circuit doing chamber tests and replacing lenses, etc. As far as I know, their analog altimeters are all have a lifetime warranty.

That is why I recommend Static line training. You do your first jumps from 3.5k, so you know what that altitude looks like, and some places only straps a alti to you after some pregression, which also makes you more aware.

Learn to eyeball it. It doesnt take much effort and is usually quite reliable. You can't always count on instruments...they are just mechanical things and shouldnt be totally relied upon. Your eyeballs can usually tell you when it time to open...so train yourself.

if/when you are in formation, you have the option to check other altimeters too. used to be easier when more folks wore chest-mounts, but can be done. If you really need to make the point; get some one's attention, indicate yours isn't working look them in the eye, then show and tap your alt, then reach gently for their's. Then those around you know that yours is questionable.

BUT don't rely 100% on the others to break off on time... they may be waiting on YOU. Eyeball the ground (as other's have mentioned).

When you are going to pull higher or at an unknow/conservative altitude, REALLY get a good/clear wave-off going.